Wireless communication systems are widely used to provide voice and data services for multiple users using a variety of access terminals such as cellular telephones, laptop computers and various multimedia devices. Such communications systems may encompass local area networks, such as IEEE 801.11 networks, cellular telephone and/or mobile broadband networks. These communication systems may use a one or more multiple access techniques, such as Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA) and others. Mobile broadband networks can conform to a number of system types or partnerships such as, General Packet Radio Service (GPRS), 3rd-Generation standards (3G), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS), the 3rd Generation Partnership Project (3GPP), Evolution-Data Optimized EV-DO, or Long Term Evolution (LTE).
Relay Nodes (RN) are network or terminal nodes that communicate with a base station, such as an enhanced node B (eNB) or user equipment (UE) through a wireless link called a Un link, and may be either in-band (IB) or out-of-band (OOB). A Uu link, on the other hand, refers to the wireless communication link between an eNB (or RN) and a user device such as a UE. For a UE, an RN may appear as an eNB. Relay Nodes (RN) were standardized within LTE Rel-10 as stationary relays, with the primary goal of increasing coverage, as described in 3GPP TS 36.213, v 10.2.0, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer for relaying operation;” and in 3GPP TS 36.216, v 10.2.0, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures,” which are incorporated herein by reference in their entirety. However, Carrier Aggregation (CA) is not supported in Rel-10 on the Un link.
In an in-band (IB) Half-Duplex (HD) RN, Un and Uu links operate in the same carrier frequency such that resource partitioning in the time domain is required between the RN's Un and Uu links to prevent RN's transmitter on one link from jamming or interfering RN's receiver on the other link. An IB HD RN is also known as Type 1 RN.
In an out-of-band (OOB) RN, Un and Uu links operate with different carrier frequencies. Here, the frequency separation is sufficient such that no resource partitioning in the time domain is required between a RN's Un and Uu links. For example, a RN's Un and Uu links may be in full-duplex. An OOB RN is also known as Type 1a RN. An in-band (IB) Full-Duplex (FD) RN is an RN where the RN's Un and Uu links operate in the same carrier frequency but do not require resource partitioning due to self-interference cancellation technique used. An IB FD RN is also known as Type 1b RN. Both IB (Half-Duplex) RNs and OOB RNs are supported in LTE Rel-10.